Conventional technology pertaining to certain embodiments of the present invention is described in the following publications inter alia:
Apparatus and methods for generating pressure waves are known e.g. from published PCT application WO 2007/135680; digital speaker devices are known e.g. from published PCT application WO 2009/066290.
Conventional noise shaping also termed sigma-delta modulation and delta-sigma modulation is described in “Understanding Delta-Sigma Data Converters” by Richard Schreier and Gabor C. Temes.
The disclosures of all publications and patent documents mentioned in the specification, and of the publications and patent documents cited therein directly or indirectly, are hereby incorporated by reference.
CountrySer. No.TitleUSA60/802,126AN APPARATUS FOR GENERATINGPRESSUREUSA60/907,450APPARATUS FOR GENERATINGPRESSURE AND METHODS OFMANUFACTURE THEREOFUSA60/872,488VOLUME CONTROLPCTPCT/IL2007/APPARATUS AND METHODS FOR000622GENERATING PRESSURE WAVESUSA60/924,203APPARATUS AND METHODS FORGENERATING PRESSURE WAVESUSAIMPROVED MANUFACTURINGPCTPCT/IL2007/DIRECT DIGITAL SPEAKER APPARATUS000618HAVING A DESIRED DIRECTIVITYPATTERNPCTPCT/IL2007/VOLUME AND TONE CONTROL IN000621DIRECT DIGITAL SPEAKERSUSA60/996,513IMPROVED SPEAKER APPARATUS ANDMETHODS USEFUL IN CONJUNCTIONTHEREWITHUSA61/136,778ACTUATOR APPARATUS WITH COMB-DRIVE COMPONENT AND METHODSUSEFUL FOR MANUFACTURING ANDOPERATING SAMEPCTPCT/IL2009/ACTUATOR APPARATUS WITH COMB-000943DRIVE COMPONENT AND METHODSUSEFUL FOR MANUFACTURING ANDOPERATING SAMEUSA61/171,946DUST PROTECTION APPARATUS FORFLAT DIGITAL LOUDSPEAKERSUSA61/476,352CORONA DISCHARGEUSA12/301,954VOLUME AND TONE CONTROL INDIRECT DIGITAL SPEAKERSPCTPCT/IL2008/DIGITAL SPEAKER APPARATUS001524USA12/301,951APPARATUS AND METHODS FORGENERATING PRESSURE WAVESUSA12/601,427DIRECT DIGITAL SPEAKER APPARATUSHAVING A DESIRED DIRECTIVITYPATTERNPCTPCT/IL2011/APPARATUS AND METHODS FOR050018INDIVIDUAL ADDRESSING AND NOISEREDUCTION IN ACTUATOR ARRAYSUSA61/468,916APPARATUS AND METHODS FORINDIVIDUAL ADDRESSING AND NOISEREDUCTION IN ACTUATOR ARRAYSUSA61/417,298METHODS FOR INDIVIDUAL ADDRESSINGAND NOISE REDUCTION IN ACTUATORARRAYS     General Description
According to an aspect of the invention, a system is disclosed, which controls an apparatus which includes a set of actuator elements, each including a moving element which moves between first and second extreme positions, wherein each actuator element of the set is included in: (a) exactly one first subset out of a plurality of non-empty first subsets (R-subsets) of the set of actuator elements; and (b) exactly one second subset out of a plurality of non-empty second subsets (C-subsets) of the set of actuator elements; the system including: (A) a processor, configured to: (i) determine a maximal number (Nltr) of moving elements which may be released from the first extreme position at a second sampling cycle in a first C-subset which includes moving elements released from the first extreme position in a first sampling cycle, based on: a number of the moving elements of the first C-subset which were released from the first extreme position in the first sampling cycle; (ii) obtain a number (Ntbr) of moving elements which, if released from the first extreme position during the second sampling cycle, enables production by the apparatus during the second sampling cycle of a physical effect, at least one attribute of which corresponds to at least one characteristic of a digital input signal; and (iii) generate one or more control commands for a group of subsets out of the first and the second    pluralities of subsets, in response to: (a) Nltr, (b) Ntbr, and (c) a first release-order indication, indicative of an order in which moving elements of the first C-subset are released from the first extreme position; wherein the group of subsets including the first C-subset; and (B) an interface for transferring the control commands to the apparatus, thereby resulting in movement of at least one moving element which is included in the first C-subset from the first extreme position.
Optionally, the first sampling cycle is the last sampling cycle before the second sampling cycle in which any moving element of the apparatus was released from the first extreme position.
Optionally, the physical effect is sound.
Optionally, the system further includes the apparatus.
Optionally, each of the set of actuator elements is an electrostatic actuator elements including the moving element which is operative to move between the first extreme position and the second extreme position, which is farther from a first electrode of said actuator element than the first extreme position, responsive to potentials applied to the first electrode and to the moving element based on control commands issued by the processor for the R-subset and the C-subset in which said moving element is included.
Optionally, the apparatus includes a first plurality of electrical connections (R-wires) interconnecting the moving elements of actuator elements in each R-subset, such that the moving element of any actuator element in each individual R-subset is electrically connected to the moving elements of all other actuator elements in the individual R-subset, and electrically isolated from the moving elements of all actuator elements not in the individual R-subset; and a second plurality of electrical connections (A-wires) interconnecting the first electrodes of actuator elements in each C-subset, such that the first electrode of any actuator element in each individual C-subset is electrically connected to the first electrode of all other actuator elements in the individual C-subset, and electrically isolated from all actuator elements not in the individual C-subset; wherein electric potentials applied to each of the R-wires and to each of the A-wires in response to control commands issued by the processor result in movements of the moving elements which together produce an outcome physical effect, at least one attribute of which corresponds to at least one characteristic of a digital input signal.   
Optionally, if a first criterion which is based on relationships between Nltr and Ntbr is met, the subgroup of subsets to which the processor generates control commands includes a second C-subset other than the first C-subset, wherein the interface is configured to transfer the control commands to the apparatus, thereby resulting in movement from the first extreme position of Nltr movable elements which are included in the first C-subset and of a number N(C2) of movable elements which are included in the second C-subset; and the processor is further configured to determine a second release-order indication, indicative of an order in which moving elements of the second C-subset are released from the first extreme position, wherein the second release-order indication is indicative of a different order than the order in which the moving elements of the first C-subset are released from the first extreme position.
Optionally, each of the first and the second release-order indications includes a binary value indicative of an order in which moving elements of a respective C-subset are released from the first extreme position.
Optionally, the system further includes a memory module configured to store permutational information indicative of an order in which moving elements of at least one of the plurality of C-subset are released from the first extreme position, wherein a control command issued by the processor for one of the at least one R-subsets is transferred to a corresponding R-subset which is selected based on the permutational information.
Optionally, the system further includes an order manager, which is configured to periodically generate swapping information indicative of at least one subgroup of swappable R-subsets such that for every individual C-subset of the plurality of C-subsets, all of the moving elements in each of that subgroup of R-subsets which are also included in the individual C-subset are in the same position, and if in movement moving in the same direction, and to periodically amend the permutational information based on the swapping information.
Optionally, N(C2) is equal or greater than Nltr, wherein the processor is configured to generate the control commands including N(C2) movement-inducing control commands which are issued to N(C2) different R-subsets, thereby causing the number of movable elements moving from the first extreme position to be N(C2); and the processor is configured so that when issuing movement-inducing control    commands at any sampling cycle to more than one C-subset, to issue movement-inducing control commands to a number of different R-subsets which is equal to or larger than a corresponding maximal number of moving elements which may be released from the first extreme position at the corresponding sampling cycle in a corresponding C-subset.
Optionally, the processor is configured to refrain from generating movement-inducing commands to any C-subset other than the first C-subset if Ntbr is larger than Nltr, if a second criterion which is based on relationships between Nltr and Ntbr is met.
Optionally, the processor is further configured so that, if generating control commands whose transfer to the apparatus results in movement from the first extreme position of Nltr moving elements which are included in the first C-subset, it further determines an additional release-order indication which includes a corresponding binary value indicative of an order in which moving elements of a corresponding C-subset are released from the first extreme position, and to set the binary value to a corresponding binary value included in the first release-order indication.
Optionally, the processor is configured to generate the control commands in response to historical information indicative of movement of elements from at least one of the extreme positions in one or more sampling cycles preceding the second sampling cycle.
Optionally, a movement from the first extreme position to the second extreme position of each moving element of the set is completed within k sampling cycles, where k is a positive integer; and the processor is configured to apply a first set of decision criteria for generating the control commands if no moving element of the set moved from the first extreme position in the preceding k−1 sampling cycle, and to otherwise apply at least one other set of decision criteria.
Optionally, the processor is configured to generate control commands whose transfer to the apparatus results in movement from the first extreme position of moving elements in which are included in the first C-subset in a number Nc1 which is smaller than a number of moving elements in the first C-subset which are positioned in the first extreme position if Ntbr is larger than Nc1, if a third criterion which is based on the historical information is fulfilled.   
Optionally, the processor is configured to execute, in each of a series of sampling cycles: (A) obtain a number (Ntbr(m)) of moving elements which, if released from the first extreme position during an m'th sampling cycle, enables production by the apparatus during the m'th sampling cycle of a physical effect, at least one attribute of which corresponds to at least one characteristic of a digital input signal; and (B) generate control commands for at least one subset of the set of movable elements, in response to Ntbr(m), to a number of the moving elements of a p'th C-subset which were released from the first extreme position in a respective preceding sampling cycle, and to a p'th release-order indication, indicative of an order in which moving elements of the p'th C-subset are released from the first extreme position at the m'th cycle.
Optionally, where intersections of any individual one of said first subsets of actuator elements and any individual one of said second subsets of actuator elements all include a uniform number of actuator elements
Optionally, the processor further include a defective actuator element counting module which is configured to process the one or more control commands and to determine a defective actuator elements error based on the control commands, wherein the apparatus suffers from defective elements noise resulting from malfunctioning actuator elements during one or more actuation clock cycles, the defective elements noise having a frequency spectrum, wherein the processor includes a noise shaping loop operative to shape the frequency spectrum of the defective elements noise based on the defective actuator elements error such that defective elements noise energy is reduced within a frequency band of interest and increased outside said band of interest.
Optionally, the system includes an override module which is configured to obtain information pertaining to a functionality level of actuator elements of the apparatus and to selectively modify at least one of the control commands, thereby preventing a releasing of a latched defective moving element.
According to an aspect of the invention, there is disclosed a method for controlling an apparatus which includes a set of actuator elements, each including a moving element which moves between first and second extreme positions, wherein each actuator element of the set is included in: (a) exactly one first subset out of a plurality of non-empty first subsets (R-subsets) of the set of actuator elements; and    (b) exactly one second subset out of a plurality of non-empty second subsets (C-subsets) of the set of actuator elements; the method including: (A) determining a maximal number (Nltr) of moving elements which may be released from the first extreme position at a second sampling cycle in a first C-subset which includes moving elements released from the first extreme position in a first sampling cycle, the determining based on a number of the moving elements of the first C-subset which were released from the first extreme position in the first sampling cycle; (B), obtaining a number (Ntbr) of moving elements which, if released from the first extreme position during the second sampling cycle, enables production by the apparatus during the second sampling cycle of a physical effect, at least one attribute of which corresponds to at least one characteristic of a digital input signal; (C) generating one or more control commands for a group of subsets out of the first and the second pluralities of subsets in response to Nltr, Ntbr, and a first release-order indication, indicative of an order in which moving elements of the first C-subset are released from the first extreme position; wherein the group of subsets including the first C-subset; and (D) transferring the control commands to the apparatus, thereby resulting in movement of at least one moving element which is included in the first C-subset from the first extreme position.
Optionally, the method further includes generating the physical effect at the second sampling cycle, resulting from movement of a group of moving elements which includes the at least one moving element.
Optionally, the first sampling cycle is the last sampling cycle before the second sampling cycle in which any moving element of the apparatus was released from the first extreme position.
Optionally, the physical effect is sound.
Optionally, each of the set of actuator elements is an electrostatic actuator elements including the moving element which is operative to move between the first extreme position and the second extreme position, which is farther from a first electrode of said actuator element than the first extreme position, responsive to potentials applied to the first electrode and to the moving element based on the control commands generated for the group of subsets which includes the R-subset and the C-subset in which said moving element is included.   
Optionally, the generating includes generating, if a first criterion which is based on relationships between Nltr and Ntbr is met, a control command for a second C-subset other than the first C-subset, wherein transferring of generated control commands results in movement from the first extreme position of Nltr movable elements which are included in the first C-subset and of a number N(C2) of movable elements which are included in the second C-subset.
Optionally, the method further includes determining a second release-order indication, indicative of an order in which moving elements of the second C-subset are released from the first extreme position, wherein the second release-order indication is indicative of a different order than the order in which the moving elements of the first C-subset are released from the first extreme position.
Optionally, each of the first and the second release-order indications includes a binary value indicative of an order in which moving elements of a respective C-subset are released from the first extreme position.
Optionally, the method further includes storing in a memory module permutational information indicative of an order in which moving elements of at least one of the plurality of C-subset are released from the first extreme position, wherein the transferring includes transferring at least one of the generated control command to at least one corresponding R-subset which is selected based on the permutational information.
Optionally, the method includes periodically generating swapping information indicative of at least one subgroup of swappable R-subsets such that for every individual C-subset of the plurality of C-subsets, all of the moving elements in each of that subgroup of R-subsets which are also included in the individual C-subset are in the same position and if in movement moving in the same direction, and to periodically amending the permutational information based on the swapping information.
Optionally, N(C2) is equal or greater than Nltr, wherein the generating includes generating control commands to the group of subsets which includes N(C2) different R-subsets, thereby causing the number of movable elements moving from the first extreme position to be N(C2); and the generating is executed according to rules which require that if a group of induced-subsets to which movement-inducing control commands are generated at any sampling cycle includes more than one C-subset,    than it also includes a number of different R-subsets which is equal to or larger than a corresponding maximal number of moving elements which may be released from the first extreme position at the corresponding sampling cycle in a corresponding C-subset.
Optionally, the generating is executed according to rules which prevent generating movement-inducing commands to any C-subset other than the first C-subset if Ntbr is larger than Nltr, if a second criterion which is based on relationships between Nltr and Ntbr is met.
Optionally, the method further includes determining an additional release-order indication which includes a corresponding binary value indicative of an order in which moving elements of a corresponding C-subset are released from the first extreme position if the generating of the control commands includes generating control commands whose transfer to the apparatus results in movement from the first extreme position of Nltr moving elements which are included in the first C-subset; wherein the determining of the additional release-order indication includes setting the binary value to a corresponding binary value included in the first release-order indication.
Optionally, the generating is responsive to historical information indicative of movement of elements from at least one of the extreme positions in one or more sampling cycles preceding the second sampling cycle.
Optionally, a movement from the first extreme position to the second extreme position of each moving element of the set is completed within k sampling cycles, where k is a positive integer; and the generating includes applying a first set of decision criteria for generating the control commands if no moving element of the set moved from the first extreme position in the preceding k−1 Sampling cycle, and to otherwise applying at least one other set of decision criteria.
Optionally, the generating includes generating control commands whose transfer to the apparatus results in movement from the first extreme position of moving elements in which are included in the first C-subset in a number Nc1 which is smaller than a number of moving elements in the first C-subset which are positioned in the first extreme position if Ntbr is larger than Nc1, if a third criterion which is based on the historical information is fulfilled.   
Optionally, the method includes executing in each of a series of sampling cycles: (A) obtaining a number (Ntbr(m)) of moving elements which, if released from the first extreme position during an m'th sampling cycle, enables production by the apparatus during the m'th sampling cycle of a physical effect, at least one attribute of which corresponds to at least one characteristic of a digital input signal; and (B) generating control commands for at least one subset of the set of movable elements, in response to Ntbr(m), to a number of the moving elements of a p'th C-subset which were released from the first extreme position in a respective preceding sampling cycle, and to a p'th release-order indication, indicative of an order in which moving elements of the p'th C-subset are released from the first extreme position at the m'th cycle.
Optionally, intersections of any individual one of said first subsets of actuator elements and any individual one of said second subsets of actuator elements all include a uniform number of actuator elements
According to an aspect of the invention, there is disclosed a program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method for controlling an apparatus which includes a set of actuator elements, each including a moving element which moves between first and second extreme positions, wherein each actuator element of the set is included in: (a) exactly one first subset out of a plurality of non-empty first subsets (R-subsets) of the set of actuator elements; and (b) exactly one second subset out of a plurality of non-empty second subsets (C-subsets) of the set of actuator elements; the method including: (A) determining a maximal number (Nltr) of moving elements which may be released from the first extreme position at a second sampling cycle in a first C-subset which includes moving elements released from the first extreme position in a first sampling cycle, the determining based on a number of the moving elements of the first C-subset which were released from the first extreme position in the first sampling cycle; (B) obtaining a number (Ntbr) of moving elements which, if released from the first extreme position during the second sampling cycle, enables production by the apparatus during the second sampling cycle of a physical effect, at least one attribute of which corresponds to at least one characteristic of a digital input signal; (C) generating one or more control commands for a group of subsets out of the first and the second pluralities of subsets in response to Nltr, Ntbr, and a first    release-order indication, indicative of an order in which moving elements of the first C-subset are released from the first extreme position; wherein the group of subsets including the first C-subset; and (D) transferring the control commands to the apparatus, thereby resulting in movement of at least one moving element which is included in the first C-subset from the first extreme position.
Optionally, and of the above variations of the disclosed method may be implemented for the computer readable code. In case additional stages or variations are disclosed, the computer readable code may include instructions for the execution of the respective stages.
It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.